Subversion Repositories Kolibri OS

Rev

Blame | Last modification | View Log | RSS feed

  1. // Iostreams base classes -*- C++ -*-
  2.  
  3. // Copyright (C) 1997-2015 Free Software Foundation, Inc.
  4. //
  5. // This file is part of the GNU ISO C++ Library.  This library is free
  6. // software; you can redistribute it and/or modify it under the
  7. // terms of the GNU General Public License as published by the
  8. // Free Software Foundation; either version 3, or (at your option)
  9. // any later version.
  10.  
  11. // This library is distributed in the hope that it will be useful,
  12. // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13. // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14. // GNU General Public License for more details.
  15.  
  16. // Under Section 7 of GPL version 3, you are granted additional
  17. // permissions described in the GCC Runtime Library Exception, version
  18. // 3.1, as published by the Free Software Foundation.
  19.  
  20. // You should have received a copy of the GNU General Public License and
  21. // a copy of the GCC Runtime Library Exception along with this program;
  22. // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  23. // <http://www.gnu.org/licenses/>.
  24.  
  25. /** @file bits/ios_base.h
  26.  *  This is an internal header file, included by other library headers.
  27.  *  Do not attempt to use it directly. @headername{ios}
  28.  */
  29.  
  30. //
  31. // ISO C++ 14882: 27.4  Iostreams base classes
  32. //
  33.  
  34. #ifndef _IOS_BASE_H
  35. #define _IOS_BASE_H 1
  36.  
  37. #pragma GCC system_header
  38.  
  39. #include <ext/atomicity.h>
  40. #include <bits/localefwd.h>
  41. #include <bits/locale_classes.h>
  42.  
  43. #if __cplusplus < 201103L
  44. # include <stdexcept>
  45. #else
  46. # include <system_error>
  47. #endif
  48.  
  49. namespace std _GLIBCXX_VISIBILITY(default)
  50. {
  51. _GLIBCXX_BEGIN_NAMESPACE_VERSION
  52.  
  53.   // The following definitions of bitmask types are enums, not ints,
  54.   // as permitted (but not required) in the standard, in order to provide
  55.   // better type safety in iostream calls.  A side effect is that
  56.   // expressions involving them are no longer compile-time constants.
  57.   enum _Ios_Fmtflags
  58.     {
  59.       _S_boolalpha      = 1L << 0,
  60.       _S_dec            = 1L << 1,
  61.       _S_fixed          = 1L << 2,
  62.       _S_hex            = 1L << 3,
  63.       _S_internal       = 1L << 4,
  64.       _S_left           = 1L << 5,
  65.       _S_oct            = 1L << 6,
  66.       _S_right          = 1L << 7,
  67.       _S_scientific     = 1L << 8,
  68.       _S_showbase       = 1L << 9,
  69.       _S_showpoint      = 1L << 10,
  70.       _S_showpos        = 1L << 11,
  71.       _S_skipws         = 1L << 12,
  72.       _S_unitbuf        = 1L << 13,
  73.       _S_uppercase      = 1L << 14,
  74.       _S_adjustfield    = _S_left | _S_right | _S_internal,
  75.       _S_basefield      = _S_dec | _S_oct | _S_hex,
  76.       _S_floatfield     = _S_scientific | _S_fixed,
  77.       _S_ios_fmtflags_end = 1L << 16,
  78.       _S_ios_fmtflags_max = __INT_MAX__,
  79.       _S_ios_fmtflags_min = ~__INT_MAX__
  80.     };
  81.  
  82.   inline _GLIBCXX_CONSTEXPR _Ios_Fmtflags
  83.   operator&(_Ios_Fmtflags __a, _Ios_Fmtflags __b)
  84.   { return _Ios_Fmtflags(static_cast<int>(__a) & static_cast<int>(__b)); }
  85.  
  86.   inline _GLIBCXX_CONSTEXPR _Ios_Fmtflags
  87.   operator|(_Ios_Fmtflags __a, _Ios_Fmtflags __b)
  88.   { return _Ios_Fmtflags(static_cast<int>(__a) | static_cast<int>(__b)); }
  89.  
  90.   inline _GLIBCXX_CONSTEXPR _Ios_Fmtflags
  91.   operator^(_Ios_Fmtflags __a, _Ios_Fmtflags __b)
  92.   { return _Ios_Fmtflags(static_cast<int>(__a) ^ static_cast<int>(__b)); }
  93.  
  94.   inline _GLIBCXX_CONSTEXPR _Ios_Fmtflags
  95.   operator~(_Ios_Fmtflags __a)
  96.   { return _Ios_Fmtflags(~static_cast<int>(__a)); }
  97.  
  98.   inline const _Ios_Fmtflags&
  99.   operator|=(_Ios_Fmtflags& __a, _Ios_Fmtflags __b)
  100.   { return __a = __a | __b; }
  101.  
  102.   inline const _Ios_Fmtflags&
  103.   operator&=(_Ios_Fmtflags& __a, _Ios_Fmtflags __b)
  104.   { return __a = __a & __b; }
  105.  
  106.   inline const _Ios_Fmtflags&
  107.   operator^=(_Ios_Fmtflags& __a, _Ios_Fmtflags __b)
  108.   { return __a = __a ^ __b; }
  109.  
  110.  
  111.   enum _Ios_Openmode
  112.     {
  113.       _S_app            = 1L << 0,
  114.       _S_ate            = 1L << 1,
  115.       _S_bin            = 1L << 2,
  116.       _S_in             = 1L << 3,
  117.       _S_out            = 1L << 4,
  118.       _S_trunc          = 1L << 5,
  119.       _S_ios_openmode_end = 1L << 16,
  120.       _S_ios_openmode_max = __INT_MAX__,
  121.       _S_ios_openmode_min = ~__INT_MAX__
  122.     };
  123.  
  124.   inline _GLIBCXX_CONSTEXPR _Ios_Openmode
  125.   operator&(_Ios_Openmode __a, _Ios_Openmode __b)
  126.   { return _Ios_Openmode(static_cast<int>(__a) & static_cast<int>(__b)); }
  127.  
  128.   inline _GLIBCXX_CONSTEXPR _Ios_Openmode
  129.   operator|(_Ios_Openmode __a, _Ios_Openmode __b)
  130.   { return _Ios_Openmode(static_cast<int>(__a) | static_cast<int>(__b)); }
  131.  
  132.   inline _GLIBCXX_CONSTEXPR _Ios_Openmode
  133.   operator^(_Ios_Openmode __a, _Ios_Openmode __b)
  134.   { return _Ios_Openmode(static_cast<int>(__a) ^ static_cast<int>(__b)); }
  135.  
  136.   inline _GLIBCXX_CONSTEXPR _Ios_Openmode
  137.   operator~(_Ios_Openmode __a)
  138.   { return _Ios_Openmode(~static_cast<int>(__a)); }
  139.  
  140.   inline const _Ios_Openmode&
  141.   operator|=(_Ios_Openmode& __a, _Ios_Openmode __b)
  142.   { return __a = __a | __b; }
  143.  
  144.   inline const _Ios_Openmode&
  145.   operator&=(_Ios_Openmode& __a, _Ios_Openmode __b)
  146.   { return __a = __a & __b; }
  147.  
  148.   inline const _Ios_Openmode&
  149.   operator^=(_Ios_Openmode& __a, _Ios_Openmode __b)
  150.   { return __a = __a ^ __b; }
  151.  
  152.  
  153.   enum _Ios_Iostate
  154.     {
  155.       _S_goodbit                = 0,
  156.       _S_badbit                 = 1L << 0,
  157.       _S_eofbit                 = 1L << 1,
  158.       _S_failbit                = 1L << 2,
  159.       _S_ios_iostate_end = 1L << 16,
  160.       _S_ios_iostate_max = __INT_MAX__,
  161.       _S_ios_iostate_min = ~__INT_MAX__
  162.     };
  163.  
  164.   inline _GLIBCXX_CONSTEXPR _Ios_Iostate
  165.   operator&(_Ios_Iostate __a, _Ios_Iostate __b)
  166.   { return _Ios_Iostate(static_cast<int>(__a) & static_cast<int>(__b)); }
  167.  
  168.   inline _GLIBCXX_CONSTEXPR _Ios_Iostate
  169.   operator|(_Ios_Iostate __a, _Ios_Iostate __b)
  170.   { return _Ios_Iostate(static_cast<int>(__a) | static_cast<int>(__b)); }
  171.  
  172.   inline _GLIBCXX_CONSTEXPR _Ios_Iostate
  173.   operator^(_Ios_Iostate __a, _Ios_Iostate __b)
  174.   { return _Ios_Iostate(static_cast<int>(__a) ^ static_cast<int>(__b)); }
  175.  
  176.   inline _GLIBCXX_CONSTEXPR _Ios_Iostate
  177.   operator~(_Ios_Iostate __a)
  178.   { return _Ios_Iostate(~static_cast<int>(__a)); }
  179.  
  180.   inline const _Ios_Iostate&
  181.   operator|=(_Ios_Iostate& __a, _Ios_Iostate __b)
  182.   { return __a = __a | __b; }
  183.  
  184.   inline const _Ios_Iostate&
  185.   operator&=(_Ios_Iostate& __a, _Ios_Iostate __b)
  186.   { return __a = __a & __b; }
  187.  
  188.   inline const  _Ios_Iostate&
  189.   operator^=(_Ios_Iostate& __a, _Ios_Iostate __b)
  190.   { return __a = __a ^ __b; }
  191.  
  192.  
  193.   enum _Ios_Seekdir
  194.     {
  195.       _S_beg = 0,
  196.       _S_cur = _GLIBCXX_STDIO_SEEK_CUR,
  197.       _S_end = _GLIBCXX_STDIO_SEEK_END,
  198.       _S_ios_seekdir_end = 1L << 16
  199.     };
  200.  
  201. #if __cplusplus >= 201103L
  202.   /// I/O error code
  203.   enum class io_errc { stream = 1 };
  204.  
  205.   template <> struct is_error_code_enum<io_errc> : public true_type { };
  206.  
  207.   const error_category& iostream_category() noexcept;
  208.  
  209.   inline error_code
  210.   make_error_code(io_errc e) noexcept
  211.   { return error_code(static_cast<int>(e), iostream_category()); }
  212.  
  213.   inline error_condition
  214.   make_error_condition(io_errc e) noexcept
  215.   { return error_condition(static_cast<int>(e), iostream_category()); }
  216. #endif
  217.  
  218.   // 27.4.2  Class ios_base
  219.   /**
  220.    *  @brief  The base of the I/O class hierarchy.
  221.    *  @ingroup io
  222.    *
  223.    *  This class defines everything that can be defined about I/O that does
  224.    *  not depend on the type of characters being input or output.  Most
  225.    *  people will only see @c ios_base when they need to specify the full
  226.    *  name of the various I/O flags (e.g., the openmodes).
  227.   */
  228.   class ios_base
  229.   {
  230. #if _GLIBCXX_USE_CXX11_ABI
  231. #if __cplusplus < 201103L
  232.     // Type that is layout-compatible with std::system_error
  233.     struct system_error : std::runtime_error
  234.     {
  235.       // Type that is layout-compatible with std::error_code
  236.       struct error_code
  237.       {
  238.         error_code() { }
  239.       private:
  240.         int             _M_value;
  241.         const void*     _M_cat;
  242.       } _M_code;
  243.     };
  244. #endif
  245. #endif
  246.   public:
  247.  
  248.     /**
  249.      *  @brief These are thrown to indicate problems with io.
  250.      *  @ingroup exceptions
  251.      *
  252.      *  27.4.2.1.1  Class ios_base::failure
  253.      */
  254. #if _GLIBCXX_USE_CXX11_ABI
  255.     class _GLIBCXX_ABI_TAG_CXX11 failure : public system_error
  256.     {
  257.     public:
  258.       explicit
  259.       failure(const string& __str);
  260.  
  261. #if __cplusplus >= 201103L
  262.       explicit
  263.       failure(const string&, const error_code&);
  264.  
  265.       explicit
  266.       failure(const char*, const error_code& = io_errc::stream);
  267. #endif
  268.  
  269.       virtual
  270.       ~failure() throw();
  271.  
  272.       virtual const char*
  273.       what() const throw();
  274.     };
  275. #else
  276.     class failure : public exception
  277.     {
  278.     public:
  279.       // _GLIBCXX_RESOLVE_LIB_DEFECTS
  280.       // 48.  Use of non-existent exception constructor
  281.       explicit
  282.       failure(const string& __str) throw();
  283.  
  284.       // This declaration is not useless:
  285.       // http://gcc.gnu.org/onlinedocs/gcc-4.3.2/gcc/Vague-Linkage.html
  286.       virtual
  287.       ~failure() throw();
  288.  
  289.       virtual const char*
  290.       what() const throw();
  291.  
  292.     private:
  293.       string _M_msg;
  294.     };
  295. #endif
  296.  
  297.     // 27.4.2.1.2  Type ios_base::fmtflags
  298.     /**
  299.      *  @brief This is a bitmask type.
  300.      *
  301.      *  @c @a _Ios_Fmtflags is implementation-defined, but it is valid to
  302.      *  perform bitwise operations on these values and expect the Right
  303.      *  Thing to happen.  Defined objects of type fmtflags are:
  304.      *  - boolalpha
  305.      *  - dec
  306.      *  - fixed
  307.      *  - hex
  308.      *  - internal
  309.      *  - left
  310.      *  - oct
  311.      *  - right
  312.      *  - scientific
  313.      *  - showbase
  314.      *  - showpoint
  315.      *  - showpos
  316.      *  - skipws
  317.      *  - unitbuf
  318.      *  - uppercase
  319.      *  - adjustfield
  320.      *  - basefield
  321.      *  - floatfield
  322.     */
  323.     typedef _Ios_Fmtflags fmtflags;
  324.  
  325.     /// Insert/extract @c bool in alphabetic rather than numeric format.
  326.     static const fmtflags boolalpha =   _S_boolalpha;
  327.  
  328.     /// Converts integer input or generates integer output in decimal base.
  329.     static const fmtflags dec =         _S_dec;
  330.  
  331.     /// Generate floating-point output in fixed-point notation.
  332.     static const fmtflags fixed =       _S_fixed;
  333.  
  334.     /// Converts integer input or generates integer output in hexadecimal base.
  335.     static const fmtflags hex =         _S_hex;
  336.  
  337.     /// Adds fill characters at a designated internal point in certain
  338.     /// generated output, or identical to @c right if no such point is
  339.     /// designated.
  340.     static const fmtflags internal =    _S_internal;
  341.  
  342.     /// Adds fill characters on the right (final positions) of certain
  343.     /// generated output.  (I.e., the thing you print is flush left.)
  344.     static const fmtflags left =        _S_left;
  345.  
  346.     /// Converts integer input or generates integer output in octal base.
  347.     static const fmtflags oct =         _S_oct;
  348.  
  349.     /// Adds fill characters on the left (initial positions) of certain
  350.     /// generated output.  (I.e., the thing you print is flush right.)
  351.     static const fmtflags right =       _S_right;
  352.  
  353.     /// Generates floating-point output in scientific notation.
  354.     static const fmtflags scientific =  _S_scientific;
  355.  
  356.     /// Generates a prefix indicating the numeric base of generated integer
  357.     /// output.
  358.     static const fmtflags showbase =    _S_showbase;
  359.  
  360.     /// Generates a decimal-point character unconditionally in generated
  361.     /// floating-point output.
  362.     static const fmtflags showpoint =   _S_showpoint;
  363.  
  364.     /// Generates a + sign in non-negative generated numeric output.
  365.     static const fmtflags showpos =     _S_showpos;
  366.  
  367.     /// Skips leading white space before certain input operations.
  368.     static const fmtflags skipws =      _S_skipws;
  369.  
  370.     /// Flushes output after each output operation.
  371.     static const fmtflags unitbuf =     _S_unitbuf;
  372.  
  373.     /// Replaces certain lowercase letters with their uppercase equivalents
  374.     /// in generated output.
  375.     static const fmtflags uppercase =   _S_uppercase;
  376.  
  377.     /// A mask of left|right|internal.  Useful for the 2-arg form of @c setf.
  378.     static const fmtflags adjustfield = _S_adjustfield;
  379.  
  380.     /// A mask of dec|oct|hex.  Useful for the 2-arg form of @c setf.
  381.     static const fmtflags basefield =   _S_basefield;
  382.  
  383.     /// A mask of scientific|fixed.  Useful for the 2-arg form of @c setf.
  384.     static const fmtflags floatfield =  _S_floatfield;
  385.  
  386.     // 27.4.2.1.3  Type ios_base::iostate
  387.     /**
  388.      *  @brief This is a bitmask type.
  389.      *
  390.      *  @c @a _Ios_Iostate is implementation-defined, but it is valid to
  391.      *  perform bitwise operations on these values and expect the Right
  392.      *  Thing to happen.  Defined objects of type iostate are:
  393.      *  - badbit
  394.      *  - eofbit
  395.      *  - failbit
  396.      *  - goodbit
  397.     */
  398.     typedef _Ios_Iostate iostate;
  399.  
  400.     /// Indicates a loss of integrity in an input or output sequence (such
  401.     /// as an irrecoverable read error from a file).
  402.     static const iostate badbit =       _S_badbit;
  403.  
  404.     /// Indicates that an input operation reached the end of an input sequence.
  405.     static const iostate eofbit =       _S_eofbit;
  406.  
  407.     /// Indicates that an input operation failed to read the expected
  408.     /// characters, or that an output operation failed to generate the
  409.     /// desired characters.
  410.     static const iostate failbit =      _S_failbit;
  411.  
  412.     /// Indicates all is well.
  413.     static const iostate goodbit =      _S_goodbit;
  414.  
  415.     // 27.4.2.1.4  Type ios_base::openmode
  416.     /**
  417.      *  @brief This is a bitmask type.
  418.      *
  419.      *  @c @a _Ios_Openmode is implementation-defined, but it is valid to
  420.      *  perform bitwise operations on these values and expect the Right
  421.      *  Thing to happen.  Defined objects of type openmode are:
  422.      *  - app
  423.      *  - ate
  424.      *  - binary
  425.      *  - in
  426.      *  - out
  427.      *  - trunc
  428.     */
  429.     typedef _Ios_Openmode openmode;
  430.  
  431.     /// Seek to end before each write.
  432.     static const openmode app =         _S_app;
  433.  
  434.     /// Open and seek to end immediately after opening.
  435.     static const openmode ate =         _S_ate;
  436.  
  437.     /// Perform input and output in binary mode (as opposed to text mode).
  438.     /// This is probably not what you think it is; see
  439.     /// https://gcc.gnu.org/onlinedocs/libstdc++/manual/fstreams.html#std.io.filestreams.binary
  440.     static const openmode binary =      _S_bin;
  441.  
  442.     /// Open for input.  Default for @c ifstream and fstream.
  443.     static const openmode in =          _S_in;
  444.  
  445.     /// Open for output.  Default for @c ofstream and fstream.
  446.     static const openmode out =         _S_out;
  447.  
  448.     /// Open for input.  Default for @c ofstream.
  449.     static const openmode trunc =       _S_trunc;
  450.  
  451.     // 27.4.2.1.5  Type ios_base::seekdir
  452.     /**
  453.      *  @brief This is an enumerated type.
  454.      *
  455.      *  @c @a _Ios_Seekdir is implementation-defined.  Defined values
  456.      *  of type seekdir are:
  457.      *  - beg
  458.      *  - cur, equivalent to @c SEEK_CUR in the C standard library.
  459.      *  - end, equivalent to @c SEEK_END in the C standard library.
  460.     */
  461.     typedef _Ios_Seekdir seekdir;
  462.  
  463.     /// Request a seek relative to the beginning of the stream.
  464.     static const seekdir beg =          _S_beg;
  465.  
  466.     /// Request a seek relative to the current position within the sequence.
  467.     static const seekdir cur =          _S_cur;
  468.  
  469.     /// Request a seek relative to the current end of the sequence.
  470.     static const seekdir end =          _S_end;
  471.  
  472.     // Annex D.6
  473.     typedef int io_state;
  474.     typedef int open_mode;
  475.     typedef int seek_dir;
  476.  
  477.     typedef std::streampos streampos;
  478.     typedef std::streamoff streamoff;
  479.  
  480.     // Callbacks;
  481.     /**
  482.      *  @brief  The set of events that may be passed to an event callback.
  483.      *
  484.      *  erase_event is used during ~ios() and copyfmt().  imbue_event is used
  485.      *  during imbue().  copyfmt_event is used during copyfmt().
  486.     */
  487.     enum event
  488.     {
  489.       erase_event,
  490.       imbue_event,
  491.       copyfmt_event
  492.     };
  493.  
  494.     /**
  495.      *  @brief  The type of an event callback function.
  496.      *  @param  __e  One of the members of the event enum.
  497.      *  @param  __b  Reference to the ios_base object.
  498.      *  @param  __i  The integer provided when the callback was registered.
  499.      *
  500.      *  Event callbacks are user defined functions that get called during
  501.      *  several ios_base and basic_ios functions, specifically imbue(),
  502.      *  copyfmt(), and ~ios().
  503.     */
  504.     typedef void (*event_callback) (event __e, ios_base& __b, int __i);
  505.  
  506.     /**
  507.      *  @brief  Add the callback __fn with parameter __index.
  508.      *  @param  __fn  The function to add.
  509.      *  @param  __index  The integer to pass to the function when invoked.
  510.      *
  511.      *  Registers a function as an event callback with an integer parameter to
  512.      *  be passed to the function when invoked.  Multiple copies of the
  513.      *  function are allowed.  If there are multiple callbacks, they are
  514.      *  invoked in the order they were registered.
  515.     */
  516.     void
  517.     register_callback(event_callback __fn, int __index);
  518.  
  519.   protected:
  520.     streamsize          _M_precision;
  521.     streamsize          _M_width;
  522.     fmtflags            _M_flags;
  523.     iostate             _M_exception;
  524.     iostate             _M_streambuf_state;
  525.  
  526.     // 27.4.2.6  Members for callbacks
  527.     // 27.4.2.6  ios_base callbacks
  528.     struct _Callback_list
  529.     {
  530.       // Data Members
  531.       _Callback_list*           _M_next;
  532.       ios_base::event_callback  _M_fn;
  533.       int                       _M_index;
  534.       _Atomic_word              _M_refcount;  // 0 means one reference.
  535.  
  536.       _Callback_list(ios_base::event_callback __fn, int __index,
  537.                      _Callback_list* __cb)
  538.       : _M_next(__cb), _M_fn(__fn), _M_index(__index), _M_refcount(0) { }
  539.  
  540.       void
  541.       _M_add_reference() { __gnu_cxx::__atomic_add_dispatch(&_M_refcount, 1); }
  542.  
  543.       // 0 => OK to delete.
  544.       int
  545.       _M_remove_reference()
  546.       {
  547.         // Be race-detector-friendly.  For more info see bits/c++config.
  548.         _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_refcount);
  549.         int __res = __gnu_cxx::__exchange_and_add_dispatch(&_M_refcount, -1);
  550.         if (__res == 0)
  551.           {
  552.             _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_refcount);
  553.           }
  554.         return __res;
  555.       }
  556.     };
  557.  
  558.      _Callback_list*    _M_callbacks;
  559.  
  560.     void
  561.     _M_call_callbacks(event __ev) throw();
  562.  
  563.     void
  564.     _M_dispose_callbacks(void) throw();
  565.  
  566.     // 27.4.2.5  Members for iword/pword storage
  567.     struct _Words
  568.     {
  569.       void*     _M_pword;
  570.       long      _M_iword;
  571.       _Words() : _M_pword(0), _M_iword(0) { }
  572.     };
  573.  
  574.     // Only for failed iword/pword calls.
  575.     _Words              _M_word_zero;
  576.  
  577.     // Guaranteed storage.
  578.     // The first 5 iword and pword slots are reserved for internal use.
  579.     enum { _S_local_word_size = 8 };
  580.     _Words              _M_local_word[_S_local_word_size];
  581.  
  582.     // Allocated storage.
  583.     int                 _M_word_size;
  584.     _Words*             _M_word;
  585.  
  586.     _Words&
  587.     _M_grow_words(int __index, bool __iword);
  588.  
  589.     // Members for locale and locale caching.
  590.     locale              _M_ios_locale;
  591.  
  592.     void
  593.     _M_init() throw();
  594.  
  595.   public:
  596.  
  597.     // 27.4.2.1.6  Class ios_base::Init
  598.     // Used to initialize standard streams. In theory, g++ could use
  599.     // -finit-priority to order this stuff correctly without going
  600.     // through these machinations.
  601.     class Init
  602.     {
  603.       friend class ios_base;
  604.     public:
  605.       Init();
  606.       ~Init();
  607.  
  608.     private:
  609.       static _Atomic_word       _S_refcount;
  610.       static bool               _S_synced_with_stdio;
  611.     };
  612.  
  613.     // [27.4.2.2] fmtflags state functions
  614.     /**
  615.      *  @brief  Access to format flags.
  616.      *  @return  The format control flags for both input and output.
  617.     */
  618.     fmtflags
  619.     flags() const
  620.     { return _M_flags; }
  621.  
  622.     /**
  623.      *  @brief  Setting new format flags all at once.
  624.      *  @param  __fmtfl  The new flags to set.
  625.      *  @return  The previous format control flags.
  626.      *
  627.      *  This function overwrites all the format flags with @a __fmtfl.
  628.     */
  629.     fmtflags
  630.     flags(fmtflags __fmtfl)
  631.     {
  632.       fmtflags __old = _M_flags;
  633.       _M_flags = __fmtfl;
  634.       return __old;
  635.     }
  636.  
  637.     /**
  638.      *  @brief  Setting new format flags.
  639.      *  @param  __fmtfl  Additional flags to set.
  640.      *  @return  The previous format control flags.
  641.      *
  642.      *  This function sets additional flags in format control.  Flags that
  643.      *  were previously set remain set.
  644.     */
  645.     fmtflags
  646.     setf(fmtflags __fmtfl)
  647.     {
  648.       fmtflags __old = _M_flags;
  649.       _M_flags |= __fmtfl;
  650.       return __old;
  651.     }
  652.  
  653.     /**
  654.      *  @brief  Setting new format flags.
  655.      *  @param  __fmtfl  Additional flags to set.
  656.      *  @param  __mask  The flags mask for @a fmtfl.
  657.      *  @return  The previous format control flags.
  658.      *
  659.      *  This function clears @a mask in the format flags, then sets
  660.      *  @a fmtfl @c & @a mask.  An example mask is @c ios_base::adjustfield.
  661.     */
  662.     fmtflags
  663.     setf(fmtflags __fmtfl, fmtflags __mask)
  664.     {
  665.       fmtflags __old = _M_flags;
  666.       _M_flags &= ~__mask;
  667.       _M_flags |= (__fmtfl & __mask);
  668.       return __old;
  669.     }
  670.  
  671.     /**
  672.      *  @brief  Clearing format flags.
  673.      *  @param  __mask  The flags to unset.
  674.      *
  675.      *  This function clears @a __mask in the format flags.
  676.     */
  677.     void
  678.     unsetf(fmtflags __mask)
  679.     { _M_flags &= ~__mask; }
  680.  
  681.     /**
  682.      *  @brief  Flags access.
  683.      *  @return  The precision to generate on certain output operations.
  684.      *
  685.      *  Be careful if you try to give a definition of @a precision here; see
  686.      *  DR 189.
  687.     */
  688.     streamsize
  689.     precision() const
  690.     { return _M_precision; }
  691.  
  692.     /**
  693.      *  @brief  Changing flags.
  694.      *  @param  __prec  The new precision value.
  695.      *  @return  The previous value of precision().
  696.     */
  697.     streamsize
  698.     precision(streamsize __prec)
  699.     {
  700.       streamsize __old = _M_precision;
  701.       _M_precision = __prec;
  702.       return __old;
  703.     }
  704.  
  705.     /**
  706.      *  @brief  Flags access.
  707.      *  @return  The minimum field width to generate on output operations.
  708.      *
  709.      *  <em>Minimum field width</em> refers to the number of characters.
  710.     */
  711.     streamsize
  712.     width() const
  713.     { return _M_width; }
  714.  
  715.     /**
  716.      *  @brief  Changing flags.
  717.      *  @param  __wide  The new width value.
  718.      *  @return  The previous value of width().
  719.     */
  720.     streamsize
  721.     width(streamsize __wide)
  722.     {
  723.       streamsize __old = _M_width;
  724.       _M_width = __wide;
  725.       return __old;
  726.     }
  727.  
  728.     // [27.4.2.4] ios_base static members
  729.     /**
  730.      *  @brief  Interaction with the standard C I/O objects.
  731.      *  @param  __sync  Whether to synchronize or not.
  732.      *  @return  True if the standard streams were previously synchronized.
  733.      *
  734.      *  The synchronization referred to is @e only that between the standard
  735.      *  C facilities (e.g., stdout) and the standard C++ objects (e.g.,
  736.      *  cout).  User-declared streams are unaffected.  See
  737.      *  https://gcc.gnu.org/onlinedocs/libstdc++/manual/fstreams.html#std.io.filestreams.binary
  738.     */
  739.     static bool
  740.     sync_with_stdio(bool __sync = true);
  741.  
  742.     // [27.4.2.3] ios_base locale functions
  743.     /**
  744.      *  @brief  Setting a new locale.
  745.      *  @param  __loc  The new locale.
  746.      *  @return  The previous locale.
  747.      *
  748.      *  Sets the new locale for this stream, and then invokes each callback
  749.      *  with imbue_event.
  750.     */
  751.     locale
  752.     imbue(const locale& __loc) throw();
  753.  
  754.     /**
  755.      *  @brief  Locale access
  756.      *  @return  A copy of the current locale.
  757.      *
  758.      *  If @c imbue(loc) has previously been called, then this function
  759.      *  returns @c loc.  Otherwise, it returns a copy of @c std::locale(),
  760.      *  the global C++ locale.
  761.     */
  762.     locale
  763.     getloc() const
  764.     { return _M_ios_locale; }
  765.  
  766.     /**
  767.      *  @brief  Locale access
  768.      *  @return  A reference to the current locale.
  769.      *
  770.      *  Like getloc above, but returns a reference instead of
  771.      *  generating a copy.
  772.     */
  773.     const locale&
  774.     _M_getloc() const
  775.     { return _M_ios_locale; }
  776.  
  777.     // [27.4.2.5] ios_base storage functions
  778.     /**
  779.      *  @brief  Access to unique indices.
  780.      *  @return  An integer different from all previous calls.
  781.      *
  782.      *  This function returns a unique integer every time it is called.  It
  783.      *  can be used for any purpose, but is primarily intended to be a unique
  784.      *  index for the iword and pword functions.  The expectation is that an
  785.      *  application calls xalloc in order to obtain an index in the iword and
  786.      *  pword arrays that can be used without fear of conflict.
  787.      *
  788.      *  The implementation maintains a static variable that is incremented and
  789.      *  returned on each invocation.  xalloc is guaranteed to return an index
  790.      *  that is safe to use in the iword and pword arrays.
  791.     */
  792.     static int
  793.     xalloc() throw();
  794.  
  795.     /**
  796.      *  @brief  Access to integer array.
  797.      *  @param  __ix  Index into the array.
  798.      *  @return  A reference to an integer associated with the index.
  799.      *
  800.      *  The iword function provides access to an array of integers that can be
  801.      *  used for any purpose.  The array grows as required to hold the
  802.      *  supplied index.  All integers in the array are initialized to 0.
  803.      *
  804.      *  The implementation reserves several indices.  You should use xalloc to
  805.      *  obtain an index that is safe to use.  Also note that since the array
  806.      *  can grow dynamically, it is not safe to hold onto the reference.
  807.     */
  808.     long&
  809.     iword(int __ix)
  810.     {
  811.       _Words& __word = (__ix < _M_word_size)
  812.                         ? _M_word[__ix] : _M_grow_words(__ix, true);
  813.       return __word._M_iword;
  814.     }
  815.  
  816.     /**
  817.      *  @brief  Access to void pointer array.
  818.      *  @param  __ix  Index into the array.
  819.      *  @return  A reference to a void* associated with the index.
  820.      *
  821.      *  The pword function provides access to an array of pointers that can be
  822.      *  used for any purpose.  The array grows as required to hold the
  823.      *  supplied index.  All pointers in the array are initialized to 0.
  824.      *
  825.      *  The implementation reserves several indices.  You should use xalloc to
  826.      *  obtain an index that is safe to use.  Also note that since the array
  827.      *  can grow dynamically, it is not safe to hold onto the reference.
  828.     */
  829.     void*&
  830.     pword(int __ix)
  831.     {
  832.       _Words& __word = (__ix < _M_word_size)
  833.                         ? _M_word[__ix] : _M_grow_words(__ix, false);
  834.       return __word._M_pword;
  835.     }
  836.  
  837.     // Destructor
  838.     /**
  839.      *  Invokes each callback with erase_event.  Destroys local storage.
  840.      *
  841.      *  Note that the ios_base object for the standard streams never gets
  842.      *  destroyed.  As a result, any callbacks registered with the standard
  843.      *  streams will not get invoked with erase_event (unless copyfmt is
  844.      *  used).
  845.     */
  846.     virtual ~ios_base();
  847.  
  848.   protected:
  849.     ios_base() throw ();
  850.  
  851. #if __cplusplus < 201103L
  852.   // _GLIBCXX_RESOLVE_LIB_DEFECTS
  853.   // 50.  Copy constructor and assignment operator of ios_base
  854.   private:
  855.     ios_base(const ios_base&);
  856.  
  857.     ios_base&
  858.     operator=(const ios_base&);
  859. #else
  860.   public:
  861.     ios_base(const ios_base&) = delete;
  862.  
  863.     ios_base&
  864.     operator=(const ios_base&) = delete;
  865.  
  866.   protected:
  867.     void
  868.     _M_move(ios_base&) noexcept;
  869.  
  870.     void
  871.     _M_swap(ios_base& __rhs) noexcept;
  872. #endif
  873.   };
  874.  
  875.   // [27.4.5.1] fmtflags manipulators
  876.   /// Calls base.setf(ios_base::boolalpha).
  877.   inline ios_base&
  878.   boolalpha(ios_base& __base)
  879.   {
  880.     __base.setf(ios_base::boolalpha);
  881.     return __base;
  882.   }
  883.  
  884.   /// Calls base.unsetf(ios_base::boolalpha).
  885.   inline ios_base&
  886.   noboolalpha(ios_base& __base)
  887.   {
  888.     __base.unsetf(ios_base::boolalpha);
  889.     return __base;
  890.   }
  891.  
  892.   /// Calls base.setf(ios_base::showbase).
  893.   inline ios_base&
  894.   showbase(ios_base& __base)
  895.   {
  896.     __base.setf(ios_base::showbase);
  897.     return __base;
  898.   }
  899.  
  900.   /// Calls base.unsetf(ios_base::showbase).
  901.   inline ios_base&
  902.   noshowbase(ios_base& __base)
  903.   {
  904.     __base.unsetf(ios_base::showbase);
  905.     return __base;
  906.   }
  907.  
  908.   /// Calls base.setf(ios_base::showpoint).
  909.   inline ios_base&
  910.   showpoint(ios_base& __base)
  911.   {
  912.     __base.setf(ios_base::showpoint);
  913.     return __base;
  914.   }
  915.  
  916.   /// Calls base.unsetf(ios_base::showpoint).
  917.   inline ios_base&
  918.   noshowpoint(ios_base& __base)
  919.   {
  920.     __base.unsetf(ios_base::showpoint);
  921.     return __base;
  922.   }
  923.  
  924.   /// Calls base.setf(ios_base::showpos).
  925.   inline ios_base&
  926.   showpos(ios_base& __base)
  927.   {
  928.     __base.setf(ios_base::showpos);
  929.     return __base;
  930.   }
  931.  
  932.   /// Calls base.unsetf(ios_base::showpos).
  933.   inline ios_base&
  934.   noshowpos(ios_base& __base)
  935.   {
  936.     __base.unsetf(ios_base::showpos);
  937.     return __base;
  938.   }
  939.  
  940.   /// Calls base.setf(ios_base::skipws).
  941.   inline ios_base&
  942.   skipws(ios_base& __base)
  943.   {
  944.     __base.setf(ios_base::skipws);
  945.     return __base;
  946.   }
  947.  
  948.   /// Calls base.unsetf(ios_base::skipws).
  949.   inline ios_base&
  950.   noskipws(ios_base& __base)
  951.   {
  952.     __base.unsetf(ios_base::skipws);
  953.     return __base;
  954.   }
  955.  
  956.   /// Calls base.setf(ios_base::uppercase).
  957.   inline ios_base&
  958.   uppercase(ios_base& __base)
  959.   {
  960.     __base.setf(ios_base::uppercase);
  961.     return __base;
  962.   }
  963.  
  964.   /// Calls base.unsetf(ios_base::uppercase).
  965.   inline ios_base&
  966.   nouppercase(ios_base& __base)
  967.   {
  968.     __base.unsetf(ios_base::uppercase);
  969.     return __base;
  970.   }
  971.  
  972.   /// Calls base.setf(ios_base::unitbuf).
  973.   inline ios_base&
  974.   unitbuf(ios_base& __base)
  975.   {
  976.      __base.setf(ios_base::unitbuf);
  977.      return __base;
  978.   }
  979.  
  980.   /// Calls base.unsetf(ios_base::unitbuf).
  981.   inline ios_base&
  982.   nounitbuf(ios_base& __base)
  983.   {
  984.      __base.unsetf(ios_base::unitbuf);
  985.      return __base;
  986.   }
  987.  
  988.   // [27.4.5.2] adjustfield manipulators
  989.   /// Calls base.setf(ios_base::internal, ios_base::adjustfield).
  990.   inline ios_base&
  991.   internal(ios_base& __base)
  992.   {
  993.      __base.setf(ios_base::internal, ios_base::adjustfield);
  994.      return __base;
  995.   }
  996.  
  997.   /// Calls base.setf(ios_base::left, ios_base::adjustfield).
  998.   inline ios_base&
  999.   left(ios_base& __base)
  1000.   {
  1001.     __base.setf(ios_base::left, ios_base::adjustfield);
  1002.     return __base;
  1003.   }
  1004.  
  1005.   /// Calls base.setf(ios_base::right, ios_base::adjustfield).
  1006.   inline ios_base&
  1007.   right(ios_base& __base)
  1008.   {
  1009.     __base.setf(ios_base::right, ios_base::adjustfield);
  1010.     return __base;
  1011.   }
  1012.  
  1013.   // [27.4.5.3] basefield manipulators
  1014.   /// Calls base.setf(ios_base::dec, ios_base::basefield).
  1015.   inline ios_base&
  1016.   dec(ios_base& __base)
  1017.   {
  1018.     __base.setf(ios_base::dec, ios_base::basefield);
  1019.     return __base;
  1020.   }
  1021.  
  1022.   /// Calls base.setf(ios_base::hex, ios_base::basefield).
  1023.   inline ios_base&
  1024.   hex(ios_base& __base)
  1025.   {
  1026.     __base.setf(ios_base::hex, ios_base::basefield);
  1027.     return __base;
  1028.   }
  1029.  
  1030.   /// Calls base.setf(ios_base::oct, ios_base::basefield).
  1031.   inline ios_base&
  1032.   oct(ios_base& __base)
  1033.   {
  1034.     __base.setf(ios_base::oct, ios_base::basefield);
  1035.     return __base;
  1036.   }
  1037.  
  1038.   // [27.4.5.4] floatfield manipulators
  1039.   /// Calls base.setf(ios_base::fixed, ios_base::floatfield).
  1040.   inline ios_base&
  1041.   fixed(ios_base& __base)
  1042.   {
  1043.     __base.setf(ios_base::fixed, ios_base::floatfield);
  1044.     return __base;
  1045.   }
  1046.  
  1047.   /// Calls base.setf(ios_base::scientific, ios_base::floatfield).
  1048.   inline ios_base&
  1049.   scientific(ios_base& __base)
  1050.   {
  1051.     __base.setf(ios_base::scientific, ios_base::floatfield);
  1052.     return __base;
  1053.   }
  1054.  
  1055. #if __cplusplus >= 201103L
  1056.   // New C++11 floatfield manipulators
  1057.  
  1058.   /// Calls
  1059.   /// base.setf(ios_base::fixed|ios_base::scientific, ios_base::floatfield)
  1060.   inline ios_base&
  1061.   hexfloat(ios_base& __base)
  1062.   {
  1063.     __base.setf(ios_base::fixed | ios_base::scientific, ios_base::floatfield);
  1064.     return __base;
  1065.   }
  1066.  
  1067.   /// Calls @c base.unsetf(ios_base::floatfield)
  1068.   inline ios_base&
  1069.   defaultfloat(ios_base& __base)
  1070.   {
  1071.     __base.unsetf(ios_base::floatfield);
  1072.     return __base;
  1073.   }
  1074. #endif
  1075.  
  1076. _GLIBCXX_END_NAMESPACE_VERSION
  1077. } // namespace
  1078.  
  1079. #endif /* _IOS_BASE_H */
  1080.